1. Field of the Invention
This invention relates generally to intravenous ("IV") catheters, and more particularly, relates to intravenous catheters which may be used to safely convey contrast media into the venous circulatory system of a patient.
In medical procedures requiring the introduction of a catheter into blood vessels, the catheter is usually positioned over a hollow needle. Typically, the introducer needle and catheter are inserted through the skin and into the blood vessel and then the introducer needle is withdrawn through the catheter, leaving the catheter in place in the blood vessel.
It is desirable to determine by reverse flow of blood through the needle that the needle and catheter have properly pierced the blood vessel. This confirms proper catheter placement. It is also desirable to protect the health practitioner from the danger presented by an exposed needle tip contaminated with bodily fluids.
2. Description of the Prior Art
The IV Catheters most commonly used for fluid delivery are designed primarily for IV drip or low pressure injections. They are not recommended for use with CT/MRI (Computed Tomography/Magnetic Resonance Imaging) procedures or power injectors which may have high pressure in the range of 350 psi. levels.
A typical over-the-needle IV catheter requires the user to remove and then dispose of a contaminated needle after the needle tip and catheter are properly located in the vein of the patient. Once the needle is withdrawn from the catheter, the user's immediate priorities are infusion set connection and site preparation, including the taping of the catheter to the patient. Because of the urgency of these procedures, the needle is normally just dropped conveniently nearby and then retrieved later. Since the needle at this time is exposed and located close to where the user is completing work with the catheter, accidental self-inflicted needle injuries are not uncommon. As the tip is quite sharp and is typically contaminated with bodily fluid, the needle may present a health risk unless steps are taken to cover the tip. For this reason, there is an increasing need to protect the user from accidental needle injury and exposure to hepatitis and AIDS.
Examples of prior art patents incorporating the use of a needle guard to shield the introducer needle after use include Purdy, et al., U.S. Pat. Nos. 5,215,528; Rossetti, 5,201,713; Lemieux, 4,952,207; Dembrowski, 4,978,344; and Moorehead, 4,177,809. Each of these prior art patent discloses the use of a shield to cover the introducer needle after contact with potentially contaminated bodily fluids.
What these systems generally fail to address is the problem of blood flowback just after needle withdrawal. Once the needle is withdrawn, the catheter hub is open to low pressure venous blood flow until the infusion set is connected. A health risk is presented by this blood flowback. One prior device, the INTIMA IV CATHETER, manufactured by Becton Dickinson and Company has attempted to address this concern by placing a rubber seal at the proximal end of the catheter hub which reseals after needle withdrawal. However, this system does not address the problem of needle sticks. Further improvements are thus needed.